1. Field of the Invention
The present invention relates to a curtain airbag device that inflates and deploys along one side of a vehicle interior for the purpose of protecting the occupant(s) in the event of a side collision or rollover of the vehicle.
2. Description of Related Technology
Curtain airbags that can protect occupants' heads, even if the vehicle rolls over following a side crash, are mounted in most cases to roof side rails, or the like, inside roof head trims above doors. Curtain airbags are typically mounted in a rolled up state so as to be able to be mounted in limited accommodation space.
When pressurized gas is supplied from an inflator in an emergency, the curtain airbag inflates and deploys rapidly. There is a risk that, as a result of this, a cushion part may contact an object around the roof side rail, such as a bracket of an assist grip, and burst. Consequently, curtain airbags or the like having means of covering the cushion part, such as a protector for protecting the cushion part, have been proposed (see for example Japanese Patent Application Laid-open No. 2009-23439, and also see Japanese Patent Application Laid-open No. 2006-306312 and Japanese Patent Application Laid-open No. 2006-168398).
One of the notable problems in the conventional techniques is a burst caused by choking of gas flow. Portions of the cushion part that are not covered by the protector expand freely and largely by the gas. Therefore, the gas flow may be choked at a bottle neck that may be formed at one end of the protector near the inflator, causing the cushion part to change its shape suddenly at this end, because of which the cushion part can readily burst.